Sleepwalking is an embarrassing and in some cases life threatening arousal disorder associated with other significant mental health problems. Diagnosis and treatment evaluation has been hampered by the problems recording relatively rare events. An ambulatory monitor recording body position largely resolves this problem. It would also be used for Restless Legs and other sleep disorders requiring separating events in relation to standing/walking, sitting or lying. Medical conditions, particularly osteoporosis, involving standing times for treatments would also use the monitor to support compliance and assess treatment efficacy. The monitor provides an enabling technology for research and clinical evaluations in these areas. Key to this monitor is the combination of IM Systems ambulatory recording technology and a unique 3-D sensor. Four easy-to-use prototypes were built. Data were successfully recorded every 30 seconds for several days from both children and adults. Phase II will include improved monitor design, clinical evaluations and integration of this position recording with activity and restless legs monitors. A home monitor will also be developed to sound a loud alarm to alert both the caregiver and the sleep walker. PROPOSED COMMERCIAL APPLICATION: The ambulatory position monitor will be marketed to all sleep disorders centers, all hospitals and medical centers with epilepsy monitoring clinics, neurologists, psychiatrists, psychologists and family doctors. The marketing plan calls for establishing this technology as the standard for evaluating and screening for sleepwalking and with increased sales reducing the price sufficiently to develop good market penetration. Marketing of a simple inexpensive commercial unit for alerting sleepwalkers or their parents.